The present invention relates to an arrangement for driving out volatile impurities from ground water and also from the ground region through which the ground water flows. More particularly, it relates to such an arrangement which operates by introducing air or other gases into an opening in the ground region and subsequent aspiration of the air with entrained contamination substances.
Arrangement of the above-mentioned general type are known in the art. The known arrangement for the purification of the ground water by pumping of air into it operates with two so-called ground lances which are introduced in two separate ground openings arranged at a distance from one another. One of the lances serves for introducing of air in the ground region, while the other ground lance has the function of aspirating the air. The air during its passage through the ground region entrains the volatile contamination substances and removes them from the ground region. The above mentioned arrangements have the disadvantage that by pumping of the gas into an opening, the impurities remain in the ground regions since the volatile gas cannot be again aspirated by the second ground lance. This disadvantage can not be eliminated by introducing several aspiration lances in the ground region. The total pumped air can not be again aspirated in any manner.